One of the big arguments against the Eolas patent (the one potentially costing Microsoft US$560
billion and Web developers a lot of headaches) was the existence of prior art in the form of the pre-Mosaic Viola browser (ironically developed at UC Berkeley)
However, the University of California and Eolas responded to Microsoft’s initial appeal about Viola proving the existence of prior art by arguing the technology in Viola is not the same as the Eolas patent (a.k.a. the ’906 patent) and Viola wasn’t in the public domain. Microsoft has ten days to respond to that response.